xref: /linux/net/sctp/ipv6.c (revision b1a54551dd9ed5ef1763b97b35a0999ca002b95c)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3  * (C) Copyright IBM Corp. 2002, 2004
4  * Copyright (c) 2001 Nokia, Inc.
5  * Copyright (c) 2001 La Monte H.P. Yarroll
6  * Copyright (c) 2002-2003 Intel Corp.
7  *
8  * This file is part of the SCTP kernel implementation
9  *
10  * SCTP over IPv6.
11  *
12  * Please send any bug reports or fixes you make to the
13  * email address(es):
14  *    lksctp developers <linux-sctp@vger.kernel.org>
15  *
16  * Written or modified by:
17  *    Le Yanqun		    <yanqun.le@nokia.com>
18  *    Hui Huang		    <hui.huang@nokia.com>
19  *    La Monte H.P. Yarroll <piggy@acm.org>
20  *    Sridhar Samudrala	    <sri@us.ibm.com>
21  *    Jon Grimm		    <jgrimm@us.ibm.com>
22  *    Ardelle Fan	    <ardelle.fan@intel.com>
23  *
24  * Based on:
25  *	linux/net/ipv6/tcp_ipv6.c
26  */
27 
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29 
30 #include <linux/module.h>
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/socket.h>
34 #include <linux/sockios.h>
35 #include <linux/net.h>
36 #include <linux/in.h>
37 #include <linux/in6.h>
38 #include <linux/netdevice.h>
39 #include <linux/init.h>
40 #include <linux/ipsec.h>
41 #include <linux/slab.h>
42 
43 #include <linux/ipv6.h>
44 #include <linux/icmpv6.h>
45 #include <linux/random.h>
46 #include <linux/seq_file.h>
47 
48 #include <net/protocol.h>
49 #include <net/ndisc.h>
50 #include <net/ip.h>
51 #include <net/ipv6.h>
52 #include <net/transp_v6.h>
53 #include <net/addrconf.h>
54 #include <net/ip6_route.h>
55 #include <net/inet_common.h>
56 #include <net/inet_ecn.h>
57 #include <net/sctp/sctp.h>
58 #include <net/udp_tunnel.h>
59 
60 #include <linux/uaccess.h>
61 
62 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
63 					 union sctp_addr *s2);
64 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
65 			      __be16 port);
66 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
67 			    const union sctp_addr *addr2);
68 
69 /* Event handler for inet6 address addition/deletion events.
70  * The sctp_local_addr_list needs to be protocted by a spin lock since
71  * multiple notifiers (say IPv4 and IPv6) may be running at the same
72  * time and thus corrupt the list.
73  * The reader side is protected with RCU.
74  */
75 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
76 				void *ptr)
77 {
78 	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
79 	struct sctp_sockaddr_entry *addr = NULL;
80 	struct sctp_sockaddr_entry *temp;
81 	struct net *net = dev_net(ifa->idev->dev);
82 	int found = 0;
83 
84 	switch (ev) {
85 	case NETDEV_UP:
86 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
87 		if (addr) {
88 			addr->a.v6.sin6_family = AF_INET6;
89 			addr->a.v6.sin6_addr = ifa->addr;
90 			addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
91 			addr->valid = 1;
92 			spin_lock_bh(&net->sctp.local_addr_lock);
93 			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
94 			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
95 			spin_unlock_bh(&net->sctp.local_addr_lock);
96 		}
97 		break;
98 	case NETDEV_DOWN:
99 		spin_lock_bh(&net->sctp.local_addr_lock);
100 		list_for_each_entry_safe(addr, temp,
101 					&net->sctp.local_addr_list, list) {
102 			if (addr->a.sa.sa_family == AF_INET6 &&
103 			    ipv6_addr_equal(&addr->a.v6.sin6_addr,
104 					    &ifa->addr) &&
105 			    addr->a.v6.sin6_scope_id == ifa->idev->dev->ifindex) {
106 				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
107 				found = 1;
108 				addr->valid = 0;
109 				list_del_rcu(&addr->list);
110 				break;
111 			}
112 		}
113 		spin_unlock_bh(&net->sctp.local_addr_lock);
114 		if (found)
115 			kfree_rcu(addr, rcu);
116 		break;
117 	}
118 
119 	return NOTIFY_DONE;
120 }
121 
122 static struct notifier_block sctp_inet6addr_notifier = {
123 	.notifier_call = sctp_inet6addr_event,
124 };
125 
126 static void sctp_v6_err_handle(struct sctp_transport *t, struct sk_buff *skb,
127 			       __u8 type, __u8 code, __u32 info)
128 {
129 	struct sctp_association *asoc = t->asoc;
130 	struct sock *sk = asoc->base.sk;
131 	int err = 0;
132 
133 	switch (type) {
134 	case ICMPV6_PKT_TOOBIG:
135 		if (ip6_sk_accept_pmtu(sk))
136 			sctp_icmp_frag_needed(sk, asoc, t, info);
137 		return;
138 	case ICMPV6_PARAMPROB:
139 		if (ICMPV6_UNK_NEXTHDR == code) {
140 			sctp_icmp_proto_unreachable(sk, asoc, t);
141 			return;
142 		}
143 		break;
144 	case NDISC_REDIRECT:
145 		sctp_icmp_redirect(sk, t, skb);
146 		return;
147 	default:
148 		break;
149 	}
150 
151 	icmpv6_err_convert(type, code, &err);
152 	if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
153 		sk->sk_err = err;
154 		sk_error_report(sk);
155 	} else {
156 		WRITE_ONCE(sk->sk_err_soft, err);
157 	}
158 }
159 
160 /* ICMP error handler. */
161 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
162 		       u8 type, u8 code, int offset, __be32 info)
163 {
164 	struct net *net = dev_net(skb->dev);
165 	struct sctp_transport *transport;
166 	struct sctp_association *asoc;
167 	__u16 saveip, savesctp;
168 	struct sock *sk;
169 
170 	/* Fix up skb to look at the embedded net header. */
171 	saveip	 = skb->network_header;
172 	savesctp = skb->transport_header;
173 	skb_reset_network_header(skb);
174 	skb_set_transport_header(skb, offset);
175 	sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
176 	/* Put back, the original pointers. */
177 	skb->network_header   = saveip;
178 	skb->transport_header = savesctp;
179 	if (!sk) {
180 		__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
181 		return -ENOENT;
182 	}
183 
184 	sctp_v6_err_handle(transport, skb, type, code, ntohl(info));
185 	sctp_err_finish(sk, transport);
186 
187 	return 0;
188 }
189 
190 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb)
191 {
192 	struct net *net = dev_net(skb->dev);
193 	struct sctp_association *asoc;
194 	struct sctp_transport *t;
195 	struct icmp6hdr *hdr;
196 	__u32 info = 0;
197 
198 	skb->transport_header += sizeof(struct udphdr);
199 	sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t);
200 	if (!sk) {
201 		__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
202 		return -ENOENT;
203 	}
204 
205 	skb->transport_header -= sizeof(struct udphdr);
206 	hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr));
207 	if (hdr->icmp6_type == NDISC_REDIRECT) {
208 		/* can't be handled without outer ip6hdr known, leave it to udpv6_err */
209 		sctp_err_finish(sk, t);
210 		return 0;
211 	}
212 	if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG)
213 		info = ntohl(hdr->icmp6_mtu);
214 	sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info);
215 
216 	sctp_err_finish(sk, t);
217 	return 1;
218 }
219 
220 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t)
221 {
222 	struct dst_entry *dst = dst_clone(t->dst);
223 	struct flowi6 *fl6 = &t->fl.u.ip6;
224 	struct sock *sk = skb->sk;
225 	struct ipv6_pinfo *np = inet6_sk(sk);
226 	__u8 tclass = np->tclass;
227 	__be32 label;
228 
229 	pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
230 		 skb->len, &fl6->saddr, &fl6->daddr);
231 
232 	if (t->dscp & SCTP_DSCP_SET_MASK)
233 		tclass = t->dscp & SCTP_DSCP_VAL_MASK;
234 
235 	if (INET_ECN_is_capable(tclass))
236 		IP6_ECN_flow_xmit(sk, fl6->flowlabel);
237 
238 	if (!(t->param_flags & SPP_PMTUD_ENABLE))
239 		skb->ignore_df = 1;
240 
241 	SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
242 
243 	if (!t->encap_port || !sctp_sk(sk)->udp_port) {
244 		int res;
245 
246 		skb_dst_set(skb, dst);
247 		rcu_read_lock();
248 		res = ip6_xmit(sk, skb, fl6, sk->sk_mark,
249 			       rcu_dereference(np->opt),
250 			       tclass, READ_ONCE(sk->sk_priority));
251 		rcu_read_unlock();
252 		return res;
253 	}
254 
255 	if (skb_is_gso(skb))
256 		skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
257 
258 	skb->encapsulation = 1;
259 	skb_reset_inner_mac_header(skb);
260 	skb_reset_inner_transport_header(skb);
261 	skb_set_inner_ipproto(skb, IPPROTO_SCTP);
262 	label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6);
263 
264 	return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr,
265 				    &fl6->daddr, tclass, ip6_dst_hoplimit(dst),
266 				    label, sctp_sk(sk)->udp_port, t->encap_port, false);
267 }
268 
269 /* Returns the dst cache entry for the given source and destination ip
270  * addresses.
271  */
272 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
273 			    struct flowi *fl, struct sock *sk)
274 {
275 	struct sctp_association *asoc = t->asoc;
276 	struct dst_entry *dst = NULL;
277 	struct flowi _fl;
278 	struct flowi6 *fl6 = &_fl.u.ip6;
279 	struct sctp_bind_addr *bp;
280 	struct ipv6_pinfo *np = inet6_sk(sk);
281 	struct sctp_sockaddr_entry *laddr;
282 	union sctp_addr *daddr = &t->ipaddr;
283 	union sctp_addr dst_saddr;
284 	struct in6_addr *final_p, final;
285 	enum sctp_scope scope;
286 	__u8 matchlen = 0;
287 
288 	memset(&_fl, 0, sizeof(_fl));
289 	fl6->daddr = daddr->v6.sin6_addr;
290 	fl6->fl6_dport = daddr->v6.sin6_port;
291 	fl6->flowi6_proto = IPPROTO_SCTP;
292 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
293 		fl6->flowi6_oif = daddr->v6.sin6_scope_id;
294 	else if (asoc)
295 		fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
296 	if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
297 		fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
298 
299 	if (inet6_test_bit(SNDFLOW, sk) &&
300 	    (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
301 		struct ip6_flowlabel *flowlabel;
302 
303 		flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
304 		if (IS_ERR(flowlabel))
305 			goto out;
306 		fl6_sock_release(flowlabel);
307 	}
308 
309 	pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
310 
311 	if (asoc)
312 		fl6->fl6_sport = htons(asoc->base.bind_addr.port);
313 
314 	if (saddr) {
315 		fl6->saddr = saddr->v6.sin6_addr;
316 		if (!fl6->fl6_sport)
317 			fl6->fl6_sport = saddr->v6.sin6_port;
318 
319 		pr_debug("src=%pI6 - ", &fl6->saddr);
320 	}
321 
322 	rcu_read_lock();
323 	final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
324 	rcu_read_unlock();
325 
326 	dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
327 	if (!asoc || saddr) {
328 		t->dst = dst;
329 		memcpy(fl, &_fl, sizeof(_fl));
330 		goto out;
331 	}
332 
333 	bp = &asoc->base.bind_addr;
334 	scope = sctp_scope(daddr);
335 	/* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
336 	 * to see if we can use it.
337 	 */
338 	if (!IS_ERR(dst)) {
339 		/* Walk through the bind address list and look for a bind
340 		 * address that matches the source address of the returned dst.
341 		 */
342 		sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
343 		rcu_read_lock();
344 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
345 			if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
346 			    (laddr->state != SCTP_ADDR_SRC &&
347 			     !asoc->src_out_of_asoc_ok))
348 				continue;
349 
350 			/* Do not compare against v4 addrs */
351 			if ((laddr->a.sa.sa_family == AF_INET6) &&
352 			    (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
353 				rcu_read_unlock();
354 				t->dst = dst;
355 				memcpy(fl, &_fl, sizeof(_fl));
356 				goto out;
357 			}
358 		}
359 		rcu_read_unlock();
360 		/* None of the bound addresses match the source address of the
361 		 * dst. So release it.
362 		 */
363 		dst_release(dst);
364 		dst = NULL;
365 	}
366 
367 	/* Walk through the bind address list and try to get the
368 	 * best source address for a given destination.
369 	 */
370 	rcu_read_lock();
371 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
372 		struct dst_entry *bdst;
373 		__u8 bmatchlen;
374 
375 		if (!laddr->valid ||
376 		    laddr->state != SCTP_ADDR_SRC ||
377 		    laddr->a.sa.sa_family != AF_INET6 ||
378 		    scope > sctp_scope(&laddr->a))
379 			continue;
380 
381 		fl6->saddr = laddr->a.v6.sin6_addr;
382 		fl6->fl6_sport = laddr->a.v6.sin6_port;
383 		final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
384 		bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
385 
386 		if (IS_ERR(bdst))
387 			continue;
388 
389 		if (ipv6_chk_addr(dev_net(bdst->dev),
390 				  &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
391 			if (!IS_ERR_OR_NULL(dst))
392 				dst_release(dst);
393 			dst = bdst;
394 			t->dst = dst;
395 			memcpy(fl, &_fl, sizeof(_fl));
396 			break;
397 		}
398 
399 		bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
400 		if (matchlen > bmatchlen) {
401 			dst_release(bdst);
402 			continue;
403 		}
404 
405 		if (!IS_ERR_OR_NULL(dst))
406 			dst_release(dst);
407 		dst = bdst;
408 		matchlen = bmatchlen;
409 		t->dst = dst;
410 		memcpy(fl, &_fl, sizeof(_fl));
411 	}
412 	rcu_read_unlock();
413 
414 out:
415 	if (!IS_ERR_OR_NULL(dst)) {
416 		struct rt6_info *rt;
417 
418 		rt = (struct rt6_info *)dst;
419 		t->dst_cookie = rt6_get_cookie(rt);
420 		pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
421 			 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
422 			 &fl->u.ip6.saddr);
423 	} else {
424 		t->dst = NULL;
425 		pr_debug("no route\n");
426 	}
427 }
428 
429 /* Returns the number of consecutive initial bits that match in the 2 ipv6
430  * addresses.
431  */
432 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
433 					 union sctp_addr *s2)
434 {
435 	return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
436 }
437 
438 /* Fills in the source address(saddr) based on the destination address(daddr)
439  * and asoc's bind address list.
440  */
441 static void sctp_v6_get_saddr(struct sctp_sock *sk,
442 			      struct sctp_transport *t,
443 			      struct flowi *fl)
444 {
445 	struct flowi6 *fl6 = &fl->u.ip6;
446 	union sctp_addr *saddr = &t->saddr;
447 
448 	pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
449 
450 	if (t->dst) {
451 		saddr->v6.sin6_family = AF_INET6;
452 		saddr->v6.sin6_addr = fl6->saddr;
453 	}
454 }
455 
456 /* Make a copy of all potential local addresses. */
457 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
458 				  struct net_device *dev)
459 {
460 	struct inet6_dev *in6_dev;
461 	struct inet6_ifaddr *ifp;
462 	struct sctp_sockaddr_entry *addr;
463 
464 	rcu_read_lock();
465 	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
466 		rcu_read_unlock();
467 		return;
468 	}
469 
470 	read_lock_bh(&in6_dev->lock);
471 	list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
472 		/* Add the address to the local list.  */
473 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
474 		if (addr) {
475 			addr->a.v6.sin6_family = AF_INET6;
476 			addr->a.v6.sin6_addr = ifp->addr;
477 			addr->a.v6.sin6_scope_id = dev->ifindex;
478 			addr->valid = 1;
479 			INIT_LIST_HEAD(&addr->list);
480 			list_add_tail(&addr->list, addrlist);
481 		}
482 	}
483 
484 	read_unlock_bh(&in6_dev->lock);
485 	rcu_read_unlock();
486 }
487 
488 /* Copy over any ip options */
489 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
490 {
491 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
492 	struct ipv6_txoptions *opt;
493 
494 	newnp = inet6_sk(newsk);
495 
496 	rcu_read_lock();
497 	opt = rcu_dereference(np->opt);
498 	if (opt) {
499 		opt = ipv6_dup_options(newsk, opt);
500 		if (!opt)
501 			pr_err("%s: Failed to copy ip options\n", __func__);
502 	}
503 	RCU_INIT_POINTER(newnp->opt, opt);
504 	rcu_read_unlock();
505 }
506 
507 /* Account for the IP options */
508 static int sctp_v6_ip_options_len(struct sock *sk)
509 {
510 	struct ipv6_pinfo *np = inet6_sk(sk);
511 	struct ipv6_txoptions *opt;
512 	int len = 0;
513 
514 	rcu_read_lock();
515 	opt = rcu_dereference(np->opt);
516 	if (opt)
517 		len = opt->opt_flen + opt->opt_nflen;
518 
519 	rcu_read_unlock();
520 	return len;
521 }
522 
523 /* Initialize a sockaddr_storage from in incoming skb. */
524 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
525 			     int is_saddr)
526 {
527 	/* Always called on head skb, so this is safe */
528 	struct sctphdr *sh = sctp_hdr(skb);
529 	struct sockaddr_in6 *sa = &addr->v6;
530 
531 	addr->v6.sin6_family = AF_INET6;
532 	addr->v6.sin6_flowinfo = 0; /* FIXME */
533 	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
534 
535 	if (is_saddr) {
536 		sa->sin6_port = sh->source;
537 		sa->sin6_addr = ipv6_hdr(skb)->saddr;
538 	} else {
539 		sa->sin6_port = sh->dest;
540 		sa->sin6_addr = ipv6_hdr(skb)->daddr;
541 	}
542 }
543 
544 /* Initialize an sctp_addr from a socket. */
545 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
546 {
547 	addr->v6.sin6_family = AF_INET6;
548 	addr->v6.sin6_port = 0;
549 	addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
550 }
551 
552 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
553 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
554 {
555 	if (addr->sa.sa_family == AF_INET) {
556 		sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
557 		sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
558 		sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
559 		sk->sk_v6_rcv_saddr.s6_addr32[3] =
560 			addr->v4.sin_addr.s_addr;
561 	} else {
562 		sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
563 	}
564 }
565 
566 /* Initialize sk->sk_daddr from sctp_addr. */
567 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
568 {
569 	if (addr->sa.sa_family == AF_INET) {
570 		sk->sk_v6_daddr.s6_addr32[0] = 0;
571 		sk->sk_v6_daddr.s6_addr32[1] = 0;
572 		sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
573 		sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
574 	} else {
575 		sk->sk_v6_daddr = addr->v6.sin6_addr;
576 	}
577 }
578 
579 /* Initialize a sctp_addr from an address parameter. */
580 static bool sctp_v6_from_addr_param(union sctp_addr *addr,
581 				    union sctp_addr_param *param,
582 				    __be16 port, int iif)
583 {
584 	if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param))
585 		return false;
586 
587 	addr->v6.sin6_family = AF_INET6;
588 	addr->v6.sin6_port = port;
589 	addr->v6.sin6_flowinfo = 0; /* BUG */
590 	addr->v6.sin6_addr = param->v6.addr;
591 	addr->v6.sin6_scope_id = iif;
592 
593 	return true;
594 }
595 
596 /* Initialize an address parameter from a sctp_addr and return the length
597  * of the address parameter.
598  */
599 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
600 				 union sctp_addr_param *param)
601 {
602 	int length = sizeof(struct sctp_ipv6addr_param);
603 
604 	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
605 	param->v6.param_hdr.length = htons(length);
606 	param->v6.addr = addr->v6.sin6_addr;
607 
608 	return length;
609 }
610 
611 /* Initialize a sctp_addr from struct in6_addr. */
612 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
613 			      __be16 port)
614 {
615 	addr->sa.sa_family = AF_INET6;
616 	addr->v6.sin6_port = port;
617 	addr->v6.sin6_flowinfo = 0;
618 	addr->v6.sin6_addr = *saddr;
619 	addr->v6.sin6_scope_id = 0;
620 }
621 
622 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
623 			      const union sctp_addr *addr2)
624 {
625 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
626 		if (addr1->sa.sa_family == AF_INET &&
627 		    addr2->sa.sa_family == AF_INET6 &&
628 		    ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
629 		    addr2->v6.sin6_addr.s6_addr32[3] ==
630 		    addr1->v4.sin_addr.s_addr)
631 			return 1;
632 
633 		if (addr2->sa.sa_family == AF_INET &&
634 		    addr1->sa.sa_family == AF_INET6 &&
635 		    ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
636 		    addr1->v6.sin6_addr.s6_addr32[3] ==
637 		    addr2->v4.sin_addr.s_addr)
638 			return 1;
639 
640 		return 0;
641 	}
642 
643 	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
644 		return 0;
645 
646 	/* If this is a linklocal address, compare the scope_id. */
647 	if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
648 	    addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
649 	    addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
650 		return 0;
651 
652 	return 1;
653 }
654 
655 /* Compare addresses exactly.
656  * v4-mapped-v6 is also in consideration.
657  */
658 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
659 			    const union sctp_addr *addr2)
660 {
661 	return __sctp_v6_cmp_addr(addr1, addr2) &&
662 	       addr1->v6.sin6_port == addr2->v6.sin6_port;
663 }
664 
665 /* Initialize addr struct to INADDR_ANY. */
666 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
667 {
668 	memset(addr, 0x00, sizeof(union sctp_addr));
669 	addr->v6.sin6_family = AF_INET6;
670 	addr->v6.sin6_port = port;
671 }
672 
673 /* Is this a wildcard address? */
674 static int sctp_v6_is_any(const union sctp_addr *addr)
675 {
676 	return ipv6_addr_any(&addr->v6.sin6_addr);
677 }
678 
679 /* Should this be available for binding?   */
680 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
681 {
682 	const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
683 	struct sock *sk = &sp->inet.sk;
684 	struct net *net = sock_net(sk);
685 	struct net_device *dev = NULL;
686 	int type;
687 
688 	type = ipv6_addr_type(in6);
689 	if (IPV6_ADDR_ANY == type)
690 		return 1;
691 	if (type == IPV6_ADDR_MAPPED) {
692 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
693 			return 0;
694 		sctp_v6_map_v4(addr);
695 		return sctp_get_af_specific(AF_INET)->available(addr, sp);
696 	}
697 	if (!(type & IPV6_ADDR_UNICAST))
698 		return 0;
699 
700 	if (sk->sk_bound_dev_if) {
701 		dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
702 		if (!dev)
703 			return 0;
704 	}
705 
706 	return ipv6_can_nonlocal_bind(net, &sp->inet) ||
707 	       ipv6_chk_addr(net, in6, dev, 0);
708 }
709 
710 /* This function checks if the address is a valid address to be used for
711  * SCTP.
712  *
713  * Output:
714  * Return 0 - If the address is a non-unicast or an illegal address.
715  * Return 1 - If the address is a unicast.
716  */
717 static int sctp_v6_addr_valid(union sctp_addr *addr,
718 			      struct sctp_sock *sp,
719 			      const struct sk_buff *skb)
720 {
721 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
722 
723 	/* Support v4-mapped-v6 address. */
724 	if (ret == IPV6_ADDR_MAPPED) {
725 		/* Note: This routine is used in input, so v4-mapped-v6
726 		 * are disallowed here when there is no sctp_sock.
727 		 */
728 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
729 			return 0;
730 		sctp_v6_map_v4(addr);
731 		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
732 	}
733 
734 	/* Is this a non-unicast address */
735 	if (!(ret & IPV6_ADDR_UNICAST))
736 		return 0;
737 
738 	return 1;
739 }
740 
741 /* What is the scope of 'addr'?  */
742 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
743 {
744 	enum sctp_scope retval;
745 	int v6scope;
746 
747 	/* The IPv6 scope is really a set of bit fields.
748 	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
749 	 */
750 
751 	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
752 	switch (v6scope) {
753 	case IFA_HOST:
754 		retval = SCTP_SCOPE_LOOPBACK;
755 		break;
756 	case IFA_LINK:
757 		retval = SCTP_SCOPE_LINK;
758 		break;
759 	case IFA_SITE:
760 		retval = SCTP_SCOPE_PRIVATE;
761 		break;
762 	default:
763 		retval = SCTP_SCOPE_GLOBAL;
764 		break;
765 	}
766 
767 	return retval;
768 }
769 
770 /* Create and initialize a new sk for the socket to be returned by accept(). */
771 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
772 					     struct sctp_association *asoc,
773 					     bool kern)
774 {
775 	struct sock *newsk;
776 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
777 	struct sctp6_sock *newsctp6sk;
778 
779 	newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
780 	if (!newsk)
781 		goto out;
782 
783 	sock_init_data(NULL, newsk);
784 
785 	sctp_copy_sock(newsk, sk, asoc);
786 	sock_reset_flag(sk, SOCK_ZAPPED);
787 
788 	newsctp6sk = (struct sctp6_sock *)newsk;
789 	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
790 
791 	sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
792 
793 	newnp = inet6_sk(newsk);
794 
795 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
796 	newnp->ipv6_mc_list = NULL;
797 	newnp->ipv6_ac_list = NULL;
798 	newnp->ipv6_fl_list = NULL;
799 
800 	sctp_v6_copy_ip_options(sk, newsk);
801 
802 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
803 	 * and getpeername().
804 	 */
805 	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
806 
807 	newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
808 
809 	if (newsk->sk_prot->init(newsk)) {
810 		sk_common_release(newsk);
811 		newsk = NULL;
812 	}
813 
814 out:
815 	return newsk;
816 }
817 
818 /* Format a sockaddr for return to user space. This makes sure the return is
819  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
820  */
821 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
822 {
823 	if (sp->v4mapped) {
824 		if (addr->sa.sa_family == AF_INET)
825 			sctp_v4_map_v6(addr);
826 	} else {
827 		if (addr->sa.sa_family == AF_INET6 &&
828 		    ipv6_addr_v4mapped(&addr->v6.sin6_addr))
829 			sctp_v6_map_v4(addr);
830 	}
831 
832 	if (addr->sa.sa_family == AF_INET) {
833 		memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
834 		return sizeof(struct sockaddr_in);
835 	}
836 	return sizeof(struct sockaddr_in6);
837 }
838 
839 /* Where did this skb come from?  */
840 static int sctp_v6_skb_iif(const struct sk_buff *skb)
841 {
842 	return inet6_iif(skb);
843 }
844 
845 static int sctp_v6_skb_sdif(const struct sk_buff *skb)
846 {
847 	return inet6_sdif(skb);
848 }
849 
850 /* Was this packet marked by Explicit Congestion Notification? */
851 static int sctp_v6_is_ce(const struct sk_buff *skb)
852 {
853 	return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
854 }
855 
856 /* Dump the v6 addr to the seq file. */
857 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
858 {
859 	seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
860 }
861 
862 static void sctp_v6_ecn_capable(struct sock *sk)
863 {
864 	inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
865 }
866 
867 /* Initialize a PF_INET msgname from a ulpevent. */
868 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
869 				     char *msgname, int *addrlen)
870 {
871 	union sctp_addr *addr;
872 	struct sctp_association *asoc;
873 	union sctp_addr *paddr;
874 
875 	if (!msgname)
876 		return;
877 
878 	addr = (union sctp_addr *)msgname;
879 	asoc = event->asoc;
880 	paddr = &asoc->peer.primary_addr;
881 
882 	if (paddr->sa.sa_family == AF_INET) {
883 		addr->v4.sin_family = AF_INET;
884 		addr->v4.sin_port = htons(asoc->peer.port);
885 		addr->v4.sin_addr = paddr->v4.sin_addr;
886 	} else {
887 		addr->v6.sin6_family = AF_INET6;
888 		addr->v6.sin6_flowinfo = 0;
889 		if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
890 			addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
891 		else
892 			addr->v6.sin6_scope_id = 0;
893 		addr->v6.sin6_port = htons(asoc->peer.port);
894 		addr->v6.sin6_addr = paddr->v6.sin6_addr;
895 	}
896 
897 	*addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
898 }
899 
900 /* Initialize a msg_name from an inbound skb. */
901 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
902 				   int *addr_len)
903 {
904 	union sctp_addr *addr;
905 	struct sctphdr *sh;
906 
907 	if (!msgname)
908 		return;
909 
910 	addr = (union sctp_addr *)msgname;
911 	sh = sctp_hdr(skb);
912 
913 	if (ip_hdr(skb)->version == 4) {
914 		addr->v4.sin_family = AF_INET;
915 		addr->v4.sin_port = sh->source;
916 		addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
917 	} else {
918 		addr->v6.sin6_family = AF_INET6;
919 		addr->v6.sin6_flowinfo = 0;
920 		addr->v6.sin6_port = sh->source;
921 		addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
922 		if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
923 			addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
924 		else
925 			addr->v6.sin6_scope_id = 0;
926 	}
927 
928 	*addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
929 }
930 
931 /* Do we support this AF? */
932 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
933 {
934 	switch (family) {
935 	case AF_INET6:
936 		return 1;
937 	/* v4-mapped-v6 addresses */
938 	case AF_INET:
939 		if (!ipv6_only_sock(sctp_opt2sk(sp)))
940 			return 1;
941 		fallthrough;
942 	default:
943 		return 0;
944 	}
945 }
946 
947 /* Address matching with wildcards allowed.  This extra level
948  * of indirection lets us choose whether a PF_INET6 should
949  * disallow any v4 addresses if we so choose.
950  */
951 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
952 			       const union sctp_addr *addr2,
953 			       struct sctp_sock *opt)
954 {
955 	struct sock *sk = sctp_opt2sk(opt);
956 	struct sctp_af *af1, *af2;
957 
958 	af1 = sctp_get_af_specific(addr1->sa.sa_family);
959 	af2 = sctp_get_af_specific(addr2->sa.sa_family);
960 
961 	if (!af1 || !af2)
962 		return 0;
963 
964 	/* If the socket is IPv6 only, v4 addrs will not match */
965 	if (ipv6_only_sock(sk) && af1 != af2)
966 		return 0;
967 
968 	/* Today, wildcard AF_INET/AF_INET6. */
969 	if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
970 		return 1;
971 
972 	if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
973 		return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
974 
975 	return __sctp_v6_cmp_addr(addr1, addr2);
976 }
977 
978 /* Verify that the provided sockaddr looks bindable.   Common verification,
979  * has already been taken care of.
980  */
981 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
982 {
983 	struct sctp_af *af;
984 
985 	/* ASSERT: address family has already been verified. */
986 	if (addr->sa.sa_family != AF_INET6)
987 		af = sctp_get_af_specific(addr->sa.sa_family);
988 	else {
989 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
990 		struct net_device *dev;
991 
992 		if (type & IPV6_ADDR_LINKLOCAL) {
993 			struct net *net;
994 			if (!addr->v6.sin6_scope_id)
995 				return 0;
996 			net = sock_net(&opt->inet.sk);
997 			rcu_read_lock();
998 			dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
999 			if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) ||
1000 				      ipv6_chk_addr(net, &addr->v6.sin6_addr,
1001 						    dev, 0))) {
1002 				rcu_read_unlock();
1003 				return 0;
1004 			}
1005 			rcu_read_unlock();
1006 		}
1007 
1008 		af = opt->pf->af;
1009 	}
1010 	return af->available(addr, opt);
1011 }
1012 
1013 /* Verify that the provided sockaddr looks sendable.   Common verification,
1014  * has already been taken care of.
1015  */
1016 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
1017 {
1018 	struct sctp_af *af = NULL;
1019 
1020 	/* ASSERT: address family has already been verified. */
1021 	if (addr->sa.sa_family != AF_INET6)
1022 		af = sctp_get_af_specific(addr->sa.sa_family);
1023 	else {
1024 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
1025 		struct net_device *dev;
1026 
1027 		if (type & IPV6_ADDR_LINKLOCAL) {
1028 			if (!addr->v6.sin6_scope_id)
1029 				return 0;
1030 			rcu_read_lock();
1031 			dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
1032 						   addr->v6.sin6_scope_id);
1033 			rcu_read_unlock();
1034 			if (!dev)
1035 				return 0;
1036 		}
1037 		af = opt->pf->af;
1038 	}
1039 
1040 	return af != NULL;
1041 }
1042 
1043 /* Fill in Supported Address Type information for INIT and INIT-ACK
1044  * chunks.   Note: In the future, we may want to look at sock options
1045  * to determine whether a PF_INET6 socket really wants to have IPV4
1046  * addresses.
1047  * Returns number of addresses supported.
1048  */
1049 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
1050 				      __be16 *types)
1051 {
1052 	types[0] = SCTP_PARAM_IPV6_ADDRESS;
1053 	if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
1054 		types[1] = SCTP_PARAM_IPV4_ADDRESS;
1055 		return 2;
1056 	}
1057 	return 1;
1058 }
1059 
1060 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1061 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1062 			int peer)
1063 {
1064 	int rc;
1065 
1066 	rc = inet6_getname(sock, uaddr, peer);
1067 
1068 	if (rc < 0)
1069 		return rc;
1070 
1071 	rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1072 					  (union sctp_addr *)uaddr);
1073 
1074 	return rc;
1075 }
1076 
1077 static const struct proto_ops inet6_seqpacket_ops = {
1078 	.family		   = PF_INET6,
1079 	.owner		   = THIS_MODULE,
1080 	.release	   = inet6_release,
1081 	.bind		   = inet6_bind,
1082 	.connect	   = sctp_inet_connect,
1083 	.socketpair	   = sock_no_socketpair,
1084 	.accept		   = inet_accept,
1085 	.getname	   = sctp_getname,
1086 	.poll		   = sctp_poll,
1087 	.ioctl		   = inet6_ioctl,
1088 	.gettstamp	   = sock_gettstamp,
1089 	.listen		   = sctp_inet_listen,
1090 	.shutdown	   = inet_shutdown,
1091 	.setsockopt	   = sock_common_setsockopt,
1092 	.getsockopt	   = sock_common_getsockopt,
1093 	.sendmsg	   = inet_sendmsg,
1094 	.recvmsg	   = inet_recvmsg,
1095 	.mmap		   = sock_no_mmap,
1096 #ifdef CONFIG_COMPAT
1097 	.compat_ioctl	   = inet6_compat_ioctl,
1098 #endif
1099 };
1100 
1101 static struct inet_protosw sctpv6_seqpacket_protosw = {
1102 	.type          = SOCK_SEQPACKET,
1103 	.protocol      = IPPROTO_SCTP,
1104 	.prot 	       = &sctpv6_prot,
1105 	.ops           = &inet6_seqpacket_ops,
1106 	.flags         = SCTP_PROTOSW_FLAG
1107 };
1108 static struct inet_protosw sctpv6_stream_protosw = {
1109 	.type          = SOCK_STREAM,
1110 	.protocol      = IPPROTO_SCTP,
1111 	.prot 	       = &sctpv6_prot,
1112 	.ops           = &inet6_seqpacket_ops,
1113 	.flags         = SCTP_PROTOSW_FLAG,
1114 };
1115 
1116 static int sctp6_rcv(struct sk_buff *skb)
1117 {
1118 	SCTP_INPUT_CB(skb)->encap_port = 0;
1119 	return sctp_rcv(skb) ? -1 : 0;
1120 }
1121 
1122 static const struct inet6_protocol sctpv6_protocol = {
1123 	.handler      = sctp6_rcv,
1124 	.err_handler  = sctp_v6_err,
1125 	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1126 };
1127 
1128 static struct sctp_af sctp_af_inet6 = {
1129 	.sa_family	   = AF_INET6,
1130 	.sctp_xmit	   = sctp_v6_xmit,
1131 	.setsockopt	   = ipv6_setsockopt,
1132 	.getsockopt	   = ipv6_getsockopt,
1133 	.get_dst	   = sctp_v6_get_dst,
1134 	.get_saddr	   = sctp_v6_get_saddr,
1135 	.copy_addrlist	   = sctp_v6_copy_addrlist,
1136 	.from_skb	   = sctp_v6_from_skb,
1137 	.from_sk	   = sctp_v6_from_sk,
1138 	.from_addr_param   = sctp_v6_from_addr_param,
1139 	.to_addr_param	   = sctp_v6_to_addr_param,
1140 	.cmp_addr	   = sctp_v6_cmp_addr,
1141 	.scope		   = sctp_v6_scope,
1142 	.addr_valid	   = sctp_v6_addr_valid,
1143 	.inaddr_any	   = sctp_v6_inaddr_any,
1144 	.is_any		   = sctp_v6_is_any,
1145 	.available	   = sctp_v6_available,
1146 	.skb_iif	   = sctp_v6_skb_iif,
1147 	.skb_sdif	   = sctp_v6_skb_sdif,
1148 	.is_ce		   = sctp_v6_is_ce,
1149 	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
1150 	.ecn_capable	   = sctp_v6_ecn_capable,
1151 	.net_header_len	   = sizeof(struct ipv6hdr),
1152 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1153 	.ip_options_len	   = sctp_v6_ip_options_len,
1154 };
1155 
1156 static struct sctp_pf sctp_pf_inet6 = {
1157 	.event_msgname = sctp_inet6_event_msgname,
1158 	.skb_msgname   = sctp_inet6_skb_msgname,
1159 	.af_supported  = sctp_inet6_af_supported,
1160 	.cmp_addr      = sctp_inet6_cmp_addr,
1161 	.bind_verify   = sctp_inet6_bind_verify,
1162 	.send_verify   = sctp_inet6_send_verify,
1163 	.supported_addrs = sctp_inet6_supported_addrs,
1164 	.create_accept_sk = sctp_v6_create_accept_sk,
1165 	.addr_to_user  = sctp_v6_addr_to_user,
1166 	.to_sk_saddr   = sctp_v6_to_sk_saddr,
1167 	.to_sk_daddr   = sctp_v6_to_sk_daddr,
1168 	.copy_ip_options = sctp_v6_copy_ip_options,
1169 	.af            = &sctp_af_inet6,
1170 };
1171 
1172 /* Initialize IPv6 support and register with socket layer.  */
1173 void sctp_v6_pf_init(void)
1174 {
1175 	/* Register the SCTP specific PF_INET6 functions. */
1176 	sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1177 
1178 	/* Register the SCTP specific AF_INET6 functions. */
1179 	sctp_register_af(&sctp_af_inet6);
1180 }
1181 
1182 void sctp_v6_pf_exit(void)
1183 {
1184 	list_del(&sctp_af_inet6.list);
1185 }
1186 
1187 /* Initialize IPv6 support and register with socket layer.  */
1188 int sctp_v6_protosw_init(void)
1189 {
1190 	int rc;
1191 
1192 	rc = proto_register(&sctpv6_prot, 1);
1193 	if (rc)
1194 		return rc;
1195 
1196 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1197 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
1198 	inet6_register_protosw(&sctpv6_stream_protosw);
1199 
1200 	return 0;
1201 }
1202 
1203 void sctp_v6_protosw_exit(void)
1204 {
1205 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1206 	inet6_unregister_protosw(&sctpv6_stream_protosw);
1207 	proto_unregister(&sctpv6_prot);
1208 }
1209 
1210 
1211 /* Register with inet6 layer. */
1212 int sctp_v6_add_protocol(void)
1213 {
1214 	/* Register notifier for inet6 address additions/deletions. */
1215 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
1216 
1217 	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1218 		return -EAGAIN;
1219 
1220 	return 0;
1221 }
1222 
1223 /* Unregister with inet6 layer. */
1224 void sctp_v6_del_protocol(void)
1225 {
1226 	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1227 	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1228 }
1229